Research On Vector Control System Of Inverter Air-Conditioner Compressor

In recent years, the standard of living of our people rising into the air more and more ordinary families. With the changes in consumption concept, the requirements for air-conditioning is no longer limited to refrigeration, heating, but also energy-efficient, healthy and comfortable. Inverter air conditioner compared to the ordinary air-conditioning has many advantages, it has been widely promoted gradually. However, the performance of inverter air conditioner there are many areas for improvement, such as low-speed range of the compressor speed fluctuations, the compressor noise and vibration problems, as well as the compressor start-up with harmonic pollution load and DC voltage drop and so on.Compressor run-time are usually high-frequency low energy efficiency, low-frequency run-time energy efficiency has improved to a greater extent. Frequency range the frequency of the compressor is about 10～130Hz, but in low-speed range, the compressor gas volume changes in the load torque ripple will be a lot of speed fluctuations, resulting in low-frequency noise and vibration.Inverter air conditioner in a sealed permanent magnet motor of the compressor, the compressor temperature exceeds 120°C, and a strong high-pressure corrosive refrigerants, limiting the application of position sensor, it is necessary to adopt control method without position sensor. If the algorithm used to estimate a more precise point of view, you can effectively reduce the noise and speed fluctuations in the compressor to improve the performance of the system.Compressor start-up with the problem of load. Colder weather in the winter when the compressor is more viscous liquid, the compressor it is very difficult start, the general use of electrical heating methods to solve this problem, this is bound to increase system power consumption. Inverter air conditioner for another shutdown in the boot, the compressor in a lot of pressure has also brought problems to start.Inverter input circuit only by the single-phase full-wave diode bridge rectifier with capacitor constitute ping wave, the input current waveform was pulse-like, with a total harmonic distortion rate of more than 100% of the power supply caused a lot of harmonic pollution; DC bus at the same time voltage fluctuations, and the average of the low capacity of the compressor is not brought into full play. Power Factor Correction (PFC) algorithm can improve the power factor, reduce current harmonics.Inverter air conditioner for the above problems, this paper has done research work are as follows:1, a detailed study of inverter air conditioner compressor of permanent magnet synchronous motor (PMSM) vector control theory, permanent magnet synchronous motor sensorless control algorithm as well as the PFC control technology.2, the development of a chip at the core TMS320LF2406 compressor drive controller, to control the overall structure of the hardware design has been optimized. In the control theory based on the software implementation of this paper, based on back-EMF observer for sensorless algorithm, the software debugging system and has done a related experiment.3, the use of compressor-driven controller on the compressor start-up phase were studied to achieve a smooth start of the compressor, even if the start-up load can be done more smoothly when the start-up. At the same time, the compressor start-up phase of the open-loop to closed-loop experimental study of a switch, so that the state of the smooth switch compressor.4, to study the performance of inverter air conditioner compressor. Of this paper, sensorless algorithm of an in-depth study of the adjustment coefficient of observer so that accurate estimates of speed, so as to effectively reduce the vibration of the compressor; of this article, as well as the motor carrier frequency and carrier frequency of the coefficients of the line changes find by experiment the minimum electrical noise carrier frequency; studied in the framework of low-speed gas compressor volume load caused by the change of torque ripple on the current load torque feedforward compensation, so that the scope of the compressor at low speed uniformity.5, the compressor controller for PFC, the use of Boost Type Power Factor Correction of high-frequency rectifiers, through the Matlab simulink simulation modeling experiments in combination with PFC control access to the best data, the compressor control system to improve power factor, greatly reduces the harmonic control system. Experiments on various current harmonic analysis, to a good control effect.